Methyl farnesoate synthesis in the lobster mandibular organ: The roles of HMG-CoA reductase and farnesoic acid O-methyltransferase
| Autor: | Jon A. Friesen, David W. Borst, Kenneth C. Holford, Sheng Li |
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| Rok vydání: | 2010 |
| Předmět: |
Male
Models Molecular medicine.medical_specialty Eyestalk ablation Physiology Molecular Sequence Data Mandible Reductase Biochemistry Eye Enucleation Gene Expression Regulation Enzymologic Article Internal medicine Hemolymph medicine Animals Amino Acid Sequence RNA Messenger Phosphorylation Molecular Biology Sequence Homology Amino Acid biology Methyltransferases Hydroxymethylglutaryl-CoA reductase O-methyltransferase Enzyme assay Nephropidae Endocrinology Phosphoprotein HMG-CoA reductase Fatty Acids Unsaturated biology.protein Hydroxymethylglutaryl CoA Reductases |
| Zdroj: | Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology. 155:49-55 |
| ISSN: | 1095-6433 |
| DOI: | 10.1016/j.cbpa.2009.09.016 |
| Popis: | Eyestalk ablation (ESA) increases crustacean production of methyl farnesoate (MF), a juvenile hormone-like compound, but the biochemical steps involved are not completely understood. We measured the activity of 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGR) and farnesoic acid O - methyl transferase (FAOMeT), an early step and the last step in MF synthesis. ESA elevated hemolymph levels of MF in male lobsters. Enzyme activity suggested that increased MF production on day one was due largely to elevated HMGR activity while changes in FAOMeT activity closely paralleled changes in MF levels on day 14. Transcript levels for HMGR and FAOMeT changed little on day one, but both increased substantially on day 14. We treated ESA males with a partially purified mandibular organ-inhibiting hormone (MOIH) and observed a significant decline in MF levels, FAOMeT activity, and FAOMeT–mRNA levels after 5 h. However, no effect was observed on HMGR activity or its mRNA indicating that they must be regulated by a separate sinus gland peptide. We confirmed that lobster HMGR was not a phosphoprotein and was not regulated by reversible phosphorylation, an important mechanism for regulating other HMGRs. Nevertheless, molecular modeling indicated that the catalytic mechanisms of lobster and mammalian HMGR were similar. |
| Databáze: | OpenAIRE |
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